This invention relates to molded hinge mechanisms, specifically the type having open slotted barrel portions which can be molded integrally with the hinge without the necessity of core inserts in the mold or a separate drilling operation.
It has been recognized in the prior art that it is desirable to mold hinge mechanisms of the type which have barrels containing open slots other than the usual closed, tubular barrels. This structure allows the hinge members to be molded without the necessity for core inserts or a separate drilling operation which adds expense to the molding process. However, it is necessary in this type of hinge mechanism to prevent the hinge members from separating when the open slots in the barrels are disposed 180.degree. apart while not interfering with the rotation of the hinge members. U.S. Pat. No. 2,500,829 to Jacobson, issued Feb. 15, 1947, discloses a hinge mechanism with a series of interfitting, coaxially aligned, open slotted barrels held together by a pin. Cooperating interlocking stop members on the axial ends of each barrel serve to limit the angular displacement of the hinge members relative to one another and prevent separation of the hinge members when the open slots in the barrels are disposed 180.degree. apart. However, the stop members which are in the form of small, interlocking pie-shaped segments, contact one another only over a relatively small surface area which limits the strength of the connection between the hinge members.